Francois Fillon, former French prime minister, member of The Republicans political party and 2017 presidential election candidate of the French centre-right, and his wife Penelope arrive for a debate organised by French private TV channel TF1 in Aubervilliers, outside Paris, France, March 20, 2017. REUTERS/Patrick Kovarik/Pool

PARIS (Reuters) - French magistrates placed the wife of conservative presidential candidate Francois Fillon under formal investigation on Tuesday over allegations she was paid hundreds of thousands of euros of public funds for work she did not do, a judicial source said.

British-born Penelope Fillon will be investigated on suspicion of complicity in misappropriating public funds, the source said.

The decision, which comes two weeks after Fillon himself was placed under formal investigation in the same case, is another blow to his faltering presidential campaign.